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Parfit argues that the size of the "cosmic endowment" can be calculated from the following argument: If Earth remains habitable for a billion more years and can sustainably support a population of more than a billion humans, then there is a potential for 10 16 (or 10,000,000,000,000,000) human lives of normal duration. [60]
An estimate on the "total number of people who have ever lived" as of 1995 was calculated by Haub (1995) at "about 105 billion births since the dawn of the human race" with a cut-off date at 50,000 BC (beginning of the Upper Paleolithic), and inclusion of a high infant mortality rate throughout pre-modern history. [13]
Life After People is a television series on which scientists, mechanical engineers, and other experts speculate about what might become of planet Earth if humanity suddenly disappeared. The featured experts also talk about the impact of human absence on the environment and the vestiges of civilization thus left behind.
Humans [3] Quaternary extinction event: 640,000, 74,000, and 13,000 years ago: Unknown; may include climate changes, massive volcanic eruptions and Humans (largely by human overhunting) [4] [5] [6] Neogene: Pliocene–Pleistocene boundary extinction: 2 Ma: Possible causes include a supernova [7] [8] or the Eltanin impact [9] [10] Middle Miocene ...
Lists of people who disappeared include those whose current whereabouts are unknown, or whose deaths are unsubstantiated: Many people who disappear are eventually declared dead in absentia . Some of these people were possibly subjected to enforced disappearance , but there is insufficient information on their subsequent fates.
Therefore, the worldwide human population density is 8 billion ÷ 510 million km 2 (197 million sq mi) = 15.7 people/km 2 (41 people/sq mi). If only the Earth's land area of 150 million km 2 (58 million sq mi) is taken into account, then human population density increases to 53.3 people/km 2 (138 people/sq mi).
When the Sun becomes 10% brighter in about a billion years, [192] Earth will suffer a moist greenhouse effect resulting in its oceans boiling away, while the Earth's liquid outer core cools due to the inner core's expansion and causes the Earth's magnetic field to shut down. In the absence of a magnetic field, charged particles from the Sun ...
Mass extinctions are characterized by the loss of at least 75% of species within a geologically short period of time (i.e., less than 2 million years). [18] [51] The Holocene extinction is also known as the "sixth extinction", as it is possibly the sixth mass extinction event, after the Ordovician–Silurian extinction events, the Late Devonian extinction, the Permian–Triassic extinction ...